Vascular implant and delivery system

ABSTRACT

A vascular implant for replacing a native heart valve comprises a self expanding stent supporting a valve body having leaflets. The stent preferably comprises an anchoring structure configured to prevent the implant from passing through the valve annulus. For delivery, the implant is compacted within a delivery device and secured at one end. During delivery the implant is partially released from the delivery device, and positioning of the implant can be verified prior to full release. The implant can be at least partially resheathed and repositioned if desired.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/761,349, filed Apr. 15, 2010, now U.S. Pat. No. 8,414,644, whichclaims priority to U.S. Provisional Application Ser. No. 61/169,367,which was filed on Apr. 15, 2009. All of the above applications arehereby incorporated herein by reference in their entirety and are to beconsidered a part of this specification.

BACKGROUND

1. Field of the Invention

The present invention relates to replacement heart valves and systemsfor delivering replacement heart valves.

2. Description of the Related Art

Human heart valves, which include the aortic, pulmonary, mitral andtricuspid valves, function essentially as one-way valves operating insynchronization with the pumping heart. The valves allow blood to flowin a downstream direction, but block blood from flowing in an upstreamdirection. Diseased heart valves exhibit impairments such as narrowingof the valve or regurgitation. Such impairments reduce the heart'sblood-pumping efficiency and can be a debilitating and life threateningcondition. For example, valve insufficiency can lead to conditions suchas heart hypertrophy and dilation of the ventricle. Thus, extensiveefforts have been made to develop methods and apparatus to repair orreplace impaired heart valves.

Prostheses exist to correct problems associated with impaired heartvalves. For example, mechanical and tissue-based heart valve prosthesescan be used to replace impaired native heart valves. More recently,substantial effort has been dedicated to developing replacement heartvalves, particularly tissue-based replacement heart valves that can bedelivered with less trauma to the patient than through open heartsurgery. Replacement valves are being designed to be delivered throughminimally invasive procedures and even percutaneous procedures. Suchreplacement valves often include a tissue-based valve body that isconnected to an expandable stent that is then delivered to the nativevalve's annulus.

Development of replacement heart valves and associated delivery systemsin which the heart valve is compacted for delivery and then controllablyexpanded for controlled placement has proven to be particularlychallenging. Delivery systems that facilitate accurate positioning andreliable placement have also proven to be challenging to develop,particularly systems that enable repositioning of the valve afterpartial deployment if it is determined that the valve is not positionedcorrectly.

SUMMARY

Accordingly, there is in the need of the art for an improved replacementheart valve and an improved system for delivering such heart valves in areliable and controlled manner. The present invention relates to animplantable heart valve design along with a system and method fordelivering and implanting the same.

As discussed in U.S. Provisional Application No. 61/169,367, inaccordance with some embodiments, a prosthetic heart valve can beattached, without sutures, to a pulmonary valve annulus, an aortic valveannulus (including cases where the native leaflets have been removed),or to an atrio-ventricular valve where the leaflets and subvalvularapparatus can remain intact. Specific attention is paid here to itsrelevance in the mitral valve position; however, the same technologycould be applied to any of the four heart valves depending on theconfiguration of the design that is used. The implant itself can becomprised of a foldable valve with a plurality of leaflets (utilizingeither bovine, equine, or porcine pericardial tissue or a syntheticmaterial), a stent frame, and fabric or tissue-based liner. The valvecan be delivered through an open-heart procedure, a minimally-invasivesurgical procedure, or remotely through a catheter-based, percutaneousapproach.

As further discussed in U.S. Provisional Application No. 61/169,367, inaccordance with some embodiments, these and other objects can beachieved by combining a stent frame with a multi-leaflet valve designand a tissue- or fabric-based liner. Some embodiments of the stent frameare made from self-expanding nitinol material; however it could also bemade from a self-expanding polymer or a balloon expandable metallicmaterial. In the expanded state, the upper portion of the stent framemay be of a larger diameter than the lower portion. The lower portionsits inside of the native valve annulus (intra-annularly), while theupper portion sits above the native valve annulus (supra-annularly).

In some embodiments, the upper and lower portions of the stent havecircular cross-sections; however, it is possible that the upper portion,the lower portion, or the entire stent frame could be formed to have anoncircular cross-section that better approximates the typicalcross-section of the native valve annulus in which the prosthetic valveis being implanted. The shoulder that is formed by the transitionbetween the different diameters of the upper and lower portions of thestent frame provides fixation on one side of the native valve annulusand prevents the implant from passing through the native annulus in theaxial direction going from the upper portion to the lower portion. Theupper portion of the stent frame houses the valve and is designed with aplurality of continuous vertical struts which eliminate foreshorteningin that region of the stent frame. As a result, the tensile forces beingexerted on the valve material are minimized as it goes from the expandedstate to the compressed state during the loading process and from thecompressed state to the expanded state during deployment process. Thelower portion of the stent frame utilizes the same annular connectionmechanism (foreshortening oval cells with anchor features) that isdescribed in U.S. Provisional Application No. 60/735,221. Said featuresof the stent frame are incorporated by reference to the extent that theyare described in U.S. Provisional Application No. 61/169,367 and U.S.patent application Ser. No. 12/084,586, published as U.S. PublicationNo. 2009/0216314, which claims priority to U.S. Provisional ApplicationNo. 60/735,221.

According to certain embodiments, multiple anchor features can extendfrom the bottom of each of the oval cells that makes up the lowerportion of the stent frame. These anchor features can be formed in sucha way so that they extend radially outward from the central axis of thestent frame and can be formed in a number of different configurations toachieve optimal fixation. Likewise, the distal tips of these anchorfeatures can have various configurations to achieve optimal tissueengagement, ranging from an atraumatic tip that will not penetrate thetissue at all to a sharp tip that will embed itself into the tissue tosome degree. The anchor features oppose the transition shoulder betweenthe upper and lower portions of the stent frame and provide fixation onthe opposite side of the native valve annulus, preventing the implantfrom passing through the native annulus in the axial direction goingfrom the lower portion to the upper portion. The foreshortening thatresults from the radial expansion of the oval cells in the lower portionof the stent frame will generate an axial clamping force on the nativevalve annulus between the transition shoulder and the tips of the anchorfeatures. The stent frame may also include some form of radio-opaquemarkers (e.g. marker bands on the anchor features) to provide forimproved visibility under fluoroscope imaging. It is also possible thatthe transition shoulder between the upper and lower sections of theframe may include small anchor features that facilitate some engagementwith the tissue on that side of the annulus.

As further discussed in U.S. Provisional Application No. 61/169,367, inaccordance with some embodiments, the valve portion of the prostheticheart valve implant can utilize the same design as that described inU.S. Provisional Application No. 61/136,716. Said features of the valveportion of U.S. Provisional Application No. 61/136,716 is incorporatedby reference to the extent that they are described in U.S. ProvisionalApplication No. 61/169,367 and U.S. patent application Ser. No.12/569,856, published as U.S. Publication No. 2010/0082094, which claimspriority to U.S. Provisional Application No. 60/136,716. In someembodiments, the outer layer of the valve material can be attached tothe interior face of the upper portion of the stent frame using suturematerial or other means. The leaflet portion of the valve material isfolded inside of the outer layer of the valve material and attached tothe outer layer and/or the stent frame at the commissural posts andalong the edges of the leaflets using sutures or other means. Theattachment locations may or may not utilize eyelet holes incorporatedinto the struts of the stent frame. In some embodiments, the location ofthe fold between the outer layer and the interior leaflet layer does notextend to the end of the stent frame.

During the delivery process, which will be described in detail below,this leaves some portion of the stent frame exposed so that blood canflow freely through the valve and the valve can begin to function priorto final deployment, which in turn, allows more time and control duringthe delivery process. The lower edge of the outer layer is attached tothe upper edge of the tissue- or fabric-based liner, which is attachedto the inside face of the lower portion of the stent frame and foldsaround to the outside face of the anchor features. In some embodiments,the liner is made from a fabric material to facilitate tissue in-growthat the annular region and, thereby, provide better leak preventionovertime. In addition, a fabric-based liner may allow for a greaterdegree of elasticity to accommodate the radial expansion and axialcontraction in the lower portion of the stent frame caused by theforeshortening process. However, the liner could also be made from aseparate piece of tissue material or could be constructed by lengtheningthe outer layer of the valve material and extending it through theintra-annular region of the stent frame, folding it around the base ofthe lower portion of the stent frame to the outside face of the anchorfeatures, and attaching the terminal edge in the central region of theanchor features, again using sutures or other means.

In some embodiments, a replacement mitral valve can be configured to bedelivered to a native mitral valve and secured relative to a nativemitral valve annulus. The replacement mitral valve can include anexpandable frame having a proximal end and a distal end and having alongitudinal axis extending between the proximal end and the distal end,the expandable frame being configured to radially expand and contractfor deployment within the native mitral valve. In some embodiments, thereplacement mitral valve can include a first anchoring portion which canbe configured to at least partially engage an atrial side of the nativemitral valve annulus, the first anchoring portion including a pluralityof circumferentially-spaced anchoring tips connected by at least one rowof circumferentially expansible elements. In some embodiments, when theexpandable frame is in an expanded configuration, the first anchoringportion can extend radially outwardly from a portion of the expandableframe that has a first cross-sectional dimension such that the at leastone row of circumferentially expansible elements can have a secondcross-sectional dimension greater than the first cross-sectionaldimension. In some embodiments, the replacement mitral valve can includea second anchoring portion distal to the first anchoring portion andhaving a plurality of anchors extending from the expandable frame whichcan be configured for placement on a ventricular side of the nativemitral valve annulus, wherein when the expandable frame is in anexpanded configuration, the plurality of anchors can extend at leastpartially proximally toward the first anchoring portion. In someembodiments, a valve body can be connected to the expandable frame. Insome embodiments, radial expansion of the expandable frame can cause thefirst anchoring portion and the second anchoring portion to draw closertogether. In some embodiments, when the expandable frame is in anexpanded configuration, tips of the plurality of anchors of the secondanchoring portion can have a third cross-sectional dimension which is atleast about the same as the second cross-sectional dimension.

In accordance with one embodiment, the present invention provides amethod of loading a device for delivering a self-expanding vascularimplant. The method may include drawing a relaxed, expanded vascularimplant through an elongate form having a decreasing diameter to a loadtube portion having a compacted diameter, engaging a locking end of theimplant with a locking mechanism disposed on a support tube, advancingan outer sheath over the engaged locking end and support tube so as tocapture the locking end between the sheath and support tube, andadvancing the outer sheath over the compacted implant so as to transferthe implant from within the load tube to within the outer sheath.

In one such embodiment, transferring the implant from within the loadtube to within the outer sheath comprises further compacting theimplant.

As discussed in U.S. Provisional Application No. 61/169,367, Inaccordance with some embodiments, accurate and controlled delivery,positioning, and deployment of the implant are achieved by using adelivery device that may consist of a steerable introducer sheath, anouter sheath, a support tube, an inner tube, and a nose cone. The innertube has an internal diameter sized to fit over a standard guide wireand would be securely attached to the nose cone, such that advancing orretracting the inner tube would also cause the nose cone to moveaccordingly. The outer diameter of the inner tube is sized to movesmoothly within the internal diameter of the support tube. The supporttube has an outer diameter sized to move smoothly within the internaldiameter of the outer sheath. The distal end of the support tube alsohas a locking feature that, when covered by the out sheath, maintains aconnection to the prosthetic heart valve implant via mating features onthe end of the stent frame and prevents the implant from being fullydeployed and released until the user chooses to do so.

Some embodiments of a trans-catheter, percutaneous system may utilize asteerable introducer sheath whose inner diameter is sized to accommodatethe outer diameter of the outer sheath and which has a separate handlethat allows for relative motion between this component and the outersheath, support tube, and inner tube as a separate system. The steerableintroducer sheath would be capable of controlled deflection in one ormore planes and would be used as needed to attain proper axial alignmentbetween the delivery catheter and the native annular plane such that thetwo were perpendicular to one another. In another embodiment, thesupport tube could be constructed to have the same steerablecharacteristics, allowing for relative motion of both the inner tube andthe outer sheath with respect to the deflectable support tube andeliminating the need for the steerable introducer sheath. In the case ofan open-chest or minimally-invasive or surgical procedure, the distalend of the delivery device could be shorter, with a stiff shaft foroptimal control. In the case of a trans-catheter or percutaneousprocedure, the distal end of the delivery device would be longer with aflexible shaft to more easily navigate the vasculature. In both cases,the hand controls at the proximal are similar, as are the mechanics ofdelivery and deployment at the distal, which are described in detailbelow.

In accordance with another embodiment, the present invention provides avascular implant delivery device. The device comprises an elongatesupport tube having a distal end, a locking mechanism being disposed ator adjacent the distal end. An elongate sheath is adapted to slide overthe support tube. A self-expanding vascular implant has a lockingmember. The support tube locking mechanism is configured to engage theimplant locking member so as to block axial movement of the implant whenthe locking mechanism and locking member are engaged. The sheath has aninner lumen sized to block the implant locking member from movingradially relative to the support tube locking mechanism sufficient torelease from the support tube locking mechanism.

In order for the prosthetic heart valve assembly to be delivered, itmust first be loaded into the delivery device. To do this severalvariations of a loading system have been devised that would be capableof controllably reducing the diameter of the stent frame (and therebyreducing the diameter of the tissue valve and fabric liner). Severalembodiments of the loading system are described and can include a funnelwith a large diameter side capable of accommodating the implant in itsexpanded form and a small diameter side that will be just larger thanthe outside diameter of the outer sheath of the delivery device. Acomponent called the octopus puller is inserted through the small sideof the funnel and attached to the end of the stent frame of theprosthetic heart valve assembly. It can then be used to pull theprosthetic heart valve assembly through the funnel and reduce thediameter as it does. With the diameter sufficiently reduced, theprosthetic heart valve assembly can be loaded into the delivery device.

In one such embodiment, the self-expanding vascular implant remainsconnected to the support tube so long as the sheath extends distallypast the support tube locking mechanism, and the device is configured sothat when the sheath is moved proximally past the support tube lockingmechanism, the implant locking member moves radially out of engagementwith the support tube.

In accordance with yet another embodiment, the present inventionprovides a method of delivering a self-expanding vascular implant. Themethod may include advancing the implant within a patient's vasculatureto a desired delivery location, the implant being advanced whilemaintained in a compacted configuration within a sheath, a first end ofthe implant being captured between the sheath and a support tube lockingmechanism. The method further includes withdrawing the sheath proximallysufficient to enable a second end of the self-expanding implant toexpand radially to a fully expanded size while the first end of theimplant remains captured. The second end of the implant is positioned ina desired position and orientation while the first end of the implantremains captured. The method further includes withdrawing the sheathproximally sufficient to release the first end of the implant.

In once such embodiment, if it is determined that the second end of theimplant is not positioned as desired, the method additionally comprisesmoving the sheath distally so as to at least partially recapture theimplant within the sheath, repositioning the delivery device, and againwithdrawing the sheath proximally sufficient to enable the second end ofthe implant to expand radially.

Other inventive embodiments and features are disclosed below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a heart valve implant having features inaccordance with one embodiment.

FIG. 2A is a plan view of a stent frame of the implant of FIG. 1 in aradially compacted configuration.

FIG. 2B shows the stent frame of FIG. 2A in a radially expandedconfiguration.

FIG. 3 schematically shows an implant as in FIGS. 1-2 deployed in anative mitral annulus of a human heart.

FIG. 4A is a plan view of a stent frame configured in accordance withanother embodiment.

FIG. 4B shows an isometric view of an embodiment of the expanded stentframe.

FIG. 5A shows a flat cutting pattern for a stent frame as in FIG. 4A.

FIG. 5B shows possible eyelet locations within the stent frame tofacilitate assembly of the tissue and/or fabric.

FIG. 5C shows another embodiment of possible eyelet locations within thestent frame to facilitate assembly of the tissue and/or fabric.

FIG. 6 shows a plan view of a stent frame in accordance with yet anotherembodiment.

FIG. 7A is a plan view of a stent frame configured in accordance withstill another embodiment.

FIG. 7B is a plan view of a stent frame configured in accordance withyet a further embodiment.

FIG. 7C is a plan view of the stent frame of FIG. 7B in a compressedconfiguration.

FIG. 8A is a plan view of a stent frame configured in accordance withyet a further embodiment.

FIG. 8B is a plan view of a stent frame configured in accordance withyet a further embodiment.

FIG. 8C is a plan view of the stent frame of FIG. 8B in a compressedconfiguration.

FIGS. 9A-E show exemplary embodiments of anchor portions for use withstent frame embodiments as discussed herein.

FIGS. 10A-D show exemplary embodiments of anchor tip portions for usewith stent frame embodiments as discussed herein.

FIG. 11A shows an embodiment of a delivery device for delivering a valveimplant in accordance with one embodiment.

FIG. 11B shows a distal portion of the delivery device of FIG. 11A.

FIGS. 11C-11D show several views of one embodiment of the deliverycatheter.

FIGS. 12A-I show a distal end of a delivery device at several stagesduring a delivery operation in accordance with a preferred embodiment.

FIGS. 13A-C show the delivery device of FIGS. 12A-I at selected stagesof the deployment operation in connection with a human heart.

FIGS. 14A-L show an embodiment of a delivery device and an embodiment ofa structure for loading an implant onto the delivery device, shown atseveral stages during a loading operation.

FIGS. 15A-H show another embodiment of a loading device and associatedmethod shown at several stages during the operation of loading animplant onto a delivery device.

FIGS. 16A and 16B show an embodiment of a multi-piece loading device inan assembled and a disassembled configuration.

FIGS. 17A-F show another embodiment of a delivery device and anembodiment of a structure for loading an implant onto such a deliverydevice, shown at selected stages during a loading operation.

FIG. 18 shows an embodiment of a prosthetic heart valve assembly.

FIGS. 19A-C show isometric views of the functioning valve after it hasbeen deployed.

FIG. 20A shows a perspective view of the expanded stent frame withfabric-liner and with an alternative bend configuration of the anchorfeatures.

FIG. 20B shows a side view of the expanded stent frame of FIG. 20A.

FIG. 20C shows a front view of the expanded stent frame of FIG. 20A.

FIG. 21 shows a cross-section view of another embodiment as it would bepositioned and anchored in the mitral valve annulus.

FIG. 22A shows the strut geometry of a stent frame in the pre-expandedcondition after the pattern has been laser cut into a tube.

FIG. 22B shows the stent of FIG. 22A in both a flat pattern and expandedconfigurations to describe the various regions of the stent framegeometry.

FIG. 23A shows a first perspective view of one embodiment of theprosthetic heart valve assembly with the valve positioned in the upperportion of the stent frame.

FIG. 23B shows a second perspective view of the embodiment of FIG. 23A.

FIG. 23C shows a third perspective view of the embodiment of FIG. 23A.

FIG. 23D shows a side view of the embodiment of FIG. 23A.

FIG. 24A shows a first perspective view of one embodiment of theprosthetic heart valve assembly with the valve positioned entirely inthe lower portion of the stent frame.

FIG. 24B shows a second perspective view of the embodiment of FIG. 24A.

FIG. 24C shows a third perspective view of the embodiment of FIG. 24A.

FIG. 24D shows a side view of the embodiment of FIG. 24A.

FIG. 25A shows a first perspective view of one embodiment of theprosthetic heart valve assembly with the valve positioned between theupper and lower portions of the stent frame and a flared diameter in thestent frame at the transition between the upper and lower portions.

FIG. 25B shows a second perspective view of the embodiment of FIG. 25A.

FIG. 25C shows a third perspective view of the embodiment of FIG. 25A.

FIG. 25D shows a side view of the embodiment of FIG. 25A.

FIGS. 26A-C show three possible variations of the cross-sectional shapeof the stent frame.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present specification and drawings disclose aspects and features ofthe invention in the context of embodiments of replacement heart valvesand delivery systems for delivering replacement heart valves. Forillustrative purposes the embodiments disclosed herein are discussed inconnection with replacing the patient's mitral valve. However, it is tobe understood that the context of a particular valve or particularfeatures of a valve should not be taken as limiting, and features of anyembodiment discussed herein can be employed in connection withprostheses and delivery systems for replacing other vascular valves, andfeatures of any embodiment can be combined with features of otherembodiments as desired and when appropriate.

As discussed in U.S. Provisional Application No. 61/169,367, referringto FIG. 18, there is shown a three dimensional view of one embodiment ofthe prosthetic heart valve assembly 528 intended to be used in theatrio-ventricular position and includes the stent frame 540, apericardial tissue valve 530, and a fabric-based liner 532. Referencenumeral 502 points to the tissue valve in the upper portion of the stentframe 540, which is the same valve design that is described in U.S.Provisional Application No. 61/136,716. Said valve design of U.S.Provisional Application No. 61/136,716 is incorporated by reference tothe extent that they are described in U.S. Provisional Application No.61/169,367 and U.S. patent application Ser. No. 12/569,856, published asU.S. Publication No. 2010/0082094, which claims priority to U.S.Provisional Application No. 60/136,716. In the mitral position, theupper portion 542 of the stent frame 540 and the tissue valve 530 aredesigned to sit in the left atrium of the heart just above the mitralvalve annulus. As noted in the figures of U.S. Provisional ApplicationNo. 61/169,367, in this embodiment, the origami valve design can attachto the upper section 542 of the frame 540 located within the leftatrium.

Reference numeral 504 points to the connection region of the stent frame540 where the shoulder 546 formed by the transition between the upperand lower portions 542, 544 of the stent frame 540 captures thelow-pressure (atrial) side of the valve annulus and the anchor features548 extending from the bottom of the lower portion 544 of the stentframe 540 captures the high-pressure (ventricular) side of the annulus.The foreshortening action in the lower portion of the stent frame 540causes the anchor features 548 to move toward the transition shoulder546 and generates an axial clamping force that securely attaches theimplant onto the valve annulus. The cell geometry in this portion of thestent frame 540 utilizes the same annular connection mechanism(foreshortening oval cells with anchor features) that is described inU.S. Provisional Application No. 60/735,221. Said cell geometry of thestent frame 540 are incorporated by reference to the extent that theyare described in U.S. Provisional Application No. 61/169,367 and U.S.patent application Ser. No. 12/084,586, published as U.S. PublicationNo. 2009/0216314, which claims priority to U.S. Provisional ApplicationNo. 60/735,221. Each anchor feature 548 is allowed to move independentlyand allows the stent frame 540 to accommodate variations in the planaranatomy of the valve annulus.

Reference numeral 506 points to the fabric-liner 532 which lines theintra-annular space on the interior face of the lower portion 544 of thestent frame 540 and wraps around to the outside face of the anchorfeatures 548 where it is securely attached using sutures or other means.As further noted in the figures of U.S. Provisional Application No.61/169,367, in this embodiment, fabric can line the intra-annular spaceand wrap around the anchors 548 on the ventricular side to preventleaks. The fabric-liner 532 facilitates tissue in-growth and provides atighter seal to the surrounding tissue to reduce the risk ofparavalvular leaks.

FIGS. 19A-C show alternative isometric views of the fully deployedprosthetic valve implant 610 with functioning valve leaflets 612. FIG.19A shows the implant 610 from the in-flow side with the valve in theopen position. FIG. 19B shows the implant 610 from the in-flow side withthe valve in the closed position. FIG. 19C shows the implant 610 fromthe out-flow side with the valve leaflets partially closed 612(mid-cycle).

With reference to FIGS. 1 and 2, another embodiment of a replacementheart valve 28 comprises a valve body 30 attached to a stent frame 40.In this embodiment, the heart valve body 30 is constructed of atissue-based media such as bovine, equine and/or porcine pericardium.Vascular tissue, as well as other natural and manmade materials such asthose described herein that are thin, flexible and durable, may also beemployed for the heart valve body.

With particular reference to FIGS. 2A and 2B, the illustrated stentframe 40 embodiment supports the valve body 30 and can be expanded froma compacted state as shown in FIG. 2A to an expanded state as shown inFIG. 2B. The illustrated stent 40 preferably is a self-expanding stentconstructed of a flexible material, preferably a shape memory materialsuch as nitinol. However, as noted in U.S. Provisional Application No.61/169,367, while a preferred embodiment of the stent frame is made fromself-expanding nitinol material, it could also be made from aself-expanding polymer or a balloon expandable metallic material. As itis self-expanding, the stent 40 is in a fully opened state, as depictedin FIG. 2B, when relaxed. The illustrated stent 40 preferably iselongate from a first end 42 to a second end 44 and is tubular with alongitudinal axis 46 and a generally circular cross section. As noted inU.S. Provisional Application No. 61/169,367, although the preferredembodiment is a circular cross-section (see FIG. 26A) in order to keepthe implant symmetric and minimize the need for radial adjustment duringdelivery, it is possible to form all or a portion of the stent body intoa non-circular cross-section. It is to be understood that in otherembodiments stents can have a non-circular cross section, such as aD-shape (see FIG. 26B), an oval (see FIG. 26C) or an otherwise ovoidcross-sectional shape. As noted in U.S. Provisional Application No.61/169,367, these are just two examples of non-circular cross-sectionswhich may prove to be more advantageous, especially with respect to theatrio-ventricular position, in facilitating optimal engagement with thenative valve annulus and minimizing the chance of paravalvular leaks.

The illustrated stent frame 40 has a non-foreshortening portion 50 and aforeshortening portion 60. The portions are joined at a transition 62between the first and second ends 42, 44. Foreshortening refers to abehavior in which the length of the stent 40 in the foreshorteningportion 60 decreases as the radius of the stent increases from thecompacted state to the expanded, deployed state. As such, in FIG. 2A,which shows the stent frame 40 in a compacted state, the foreshorteningportion 60 of the stent frame 40 is longer than when the stent is in theexpanded state illustrated in FIG. 2B.

With continued reference to FIG. 2B, the non-foreshortening portion 50of the illustrated stent 40 comprises a plurality of rows or rings 64a-c of circumferentially expansible elements, or struts 65, arranged ina zigzag pattern. The struts 65 are configured to expand and contractwith a change in radius of the stent 40. In the illustrated embodiment,the stent has three such rings 64 a-c. It is to be understood that moreor fewer rings can be employed as desired to accomplish the purposes ofthis stent frame.

In the illustrated embodiment, the respective ends of eachcircumferential undulating strut 65 join an adjacent strut 65 at an apex66, 68 which is, in at least some embodiments, an area of preferentialbending. In the illustrated embodiment, the zigzag pattern of the rings64 a-c are generally in phase with one another. It is to be understoodthat, in other embodiments, all or most of the rings can be in phasewith one another or out of phase as desired.

With continued reference to FIG. 2B, longitudinal struts 70 extendtransversely across the rings 64 a-c of the nonforeshortening portion 50from the first end 42 of the frame 40 to the transition 62. Moreparticularly, each ring 64 shares a common longitudinal strut 70. Thelongitudinal struts 70 extend through apices 66 of adjacent rings 64,and preferably extend the entire length of the nonforeshortening portion50. Preferably, the longitudinal struts 70 comprise a nonexpandable rodor bar. The apices 66 that are connected to the longitudinal struts 70are referred to as “connected” apices 66. Apices 68 not connected tolongitudinal struts 70 are referred to as “free” apices 68.

As noted above, the longitudinal struts 70 are not substantiallyexpandable in a longitudinal direction. As such, even though theundulating struts 65 provide flexibility in radial expansion orcompaction, as the stent 40 changes radial size between the compactedand expanded states, the longitudinal length of the stent in thenonforeshortening portion 50 remains substantially unchanged. In otherembodiments, the longitudinal struts may include expansible elementsthat may allow the struts to expand somewhat longitudinally. However,such longitudinal expansion would not be directly tied to any change instrut radius.

In the illustrated embodiment, a first ring 64 a is disposed adjacentthe first end 42 of the stent and a second ring 64 b is disposedadjacent the first ring 64 a. A set of first eyelets 72 is formed at theconnected apices 66 of the second ring 64 b. A set of second eyelets 74is also formed at the second ends of each longitudinal strut 70, whichin the illustrated embodiment is also at the transition 62. In a thirdring 64 c, the free apices 68 each comprise a protuberance 80 extendingtherefrom, which protuberance can also be referred to as an apicalanchor 80. Preferably the apical anchor 80 terminates at a tip 82.Preferably the struts 65 in the third ring 64 c are pre-shaped so as toflare radially outwardly when the stent frame 40 is in an expanded stateas shown in FIGS. 1 and 2.

With continued reference to FIGS. 2A and 2B, the foreshortening portion60 of the illustrated stent frame 40 comprises a ring 84 of generallydiamond-shaped cells 86 connected to one another at connectors 88. Afirst end of each cell 86 is connected to the nonforeshortening portion50 at the second eyelets 74. The shape of the foreshortening cells 86 issuch that as the stent frame 40 is radially compacted, theforeshortening portion 60 of the stent becomes longitudinally longerand, correspondingly, when the stent frame 40 is expanded radially, theforeshortening portion 60 shortens.

A second end of each cell 86 in the foreshortening portion 60 definesthe second end 44 of the stent 40 and also defines a base of an endanchor 90 that extends generally radially outwardly and toward the firstend 42 of the stent. An anchor eyelet 92 is formed in each end anchor90, preferably between the base and a tip 94 of each anchor 90.

A first distance is defined between the tips 82, 94 of opposing apicaland end anchors 80, 90 when the stent 40 is in the compacted state, anda second distance is defined between the tips 82, 94 of opposing anchors80, 90 when the stent 40 is in the expanded state. As shown, the seconddistance is substantially less than the first distance. As such, due tolongitudinal shortening of the foreshortening portion 60, the anchors80, 90 cooperate to grasp onto tissues so as to hold the stent in place.

In preferred embodiments, the stent 40 may be deployed into a heartvalve annulus, and positioned when compacted so that the tips 82, 94 ofthe opposing anchors 80, 90 are disposed on opposite sides of the nativeannulus. As the stent is expanded, the opposing anchors are drawn closertogether so as to grasp opposite sides of the native annulus andsecurely hold the stent in position. As such, the stent can be heldsecurely in position without requiring a substantial radial forceagainst the native annulus.

Applicant's U.S. patent application Ser. No. 12/084,586, which waspublished on Aug. 27, 2009 as U.S. Publication No. 2009/0216314,discusses embodiments of foreshortening stents with anchors, and can bereferred to for further discussion of certain aspects of the illustratedstent embodiment. The discussion in this application concerningstructure and operation of embodiments of a foreshortening stent,particularly a foreshortening stent having anchors, is expresslyincorporated by reference herein.

Applicant's U.S. patent application Ser. No. 12/569,856, which waspublished on Apr. 1, 2010 as U.S. Publication No. 2010/0082094,discusses several additional embodiments of stents and associated valvebodies, and can be referred to for further explanation and discussion ofadditional features and embodiments thereof. The entirety of thisapplication is also expressly incorporated by reference herein.

With particular reference again to FIG. 1, in this embodiment the valvebody 30 is disposed inside the stent 40. More specifically, a skirtportion 96 of the valve body 30 is sewn to the first eyelets 72 of thestent. A hemmed upstream end of the valve body 30 engages the firsteyelets 72 in the nonforeshortening portion 50 of the stent 40. Valveleaflets are attached to the skirt portion and are configured to openand close during valve operation.

An elongate tubular portion 102 of flexible, longitudinally expandablefabric is attached to a downstream end 104 of the skirt portion 96 inthe illustrated embodiment. More particularly, a first end of the fabric102 is sewn to the downstream end 104 of the skirt portion about thecircumference of the skirt portion by a downstream seam, which alsoconnects to the second eyelets 74 of the stent frame 40. Preferably, thefabric 102 is also sewn to the foreshortening cells 86 at several pointsby connector stitches 106.

In the illustrated embodiment, the fabric 102 curves around the secondend of the stent frame 40, generally following the curvature of the endanchors 90. A second end of the fabric portion 102 is sewn to the anchoreyelets 92. Preferably, the flexible fabric 102 is sufficientlyexpandable to move with the foreshortening portion 60 as the stent 40moves between the compacted state and the deployed, relaxed expandedstate. As such, in the illustrated embodiment, the tissue valve body 30is confined to the nonforeshortening portion 50 of the stent and theflexible fabric 102 spans the foreshortening portion 60 of the stent.Thus, the tissue valve body 30 is not subject to longitudinal expansionand contraction with the stent 40.

With reference next to FIG. 3, a schematic representation of the heartvalve 28 as discussed above in connection with FIGS. 1 and 2 is depictedinstalled in a human heart 110. The heart is shown in cross-section, andrepresents typical anatomy, including a left atrium 112 and leftventricle 114. The left ventricle 114 is defined by a muscular wall 116.The left atrium 112 and left ventricle 114 communicate with one anotherthrough a mitral annulus 120. Also shown schematically in FIG. 3 is anative anterior mitral leaflet 122 having chordae tendinae 124 thatconnect a downstream end of the anterior mitral leaflet 122 to themuscle wall 116 of the left ventricle 114. A left ventricle outflowtract 126 extends toward the top of the left ventricle 114.

As shown in FIG. 3, the valve 28 of FIGS. 1 and 2 is disposed so thatthe mitral annulus 120 is grasped between the end anchors 90 and apicalanchors 80 in accordance with a method of aligning and deployment of thestent 40 discussed previously. As such, all or most of the stent 40extends into the left atrium. The portion of the stent 40 disposedupstream of the annulus 120 can be referred to as being positionedsupra-annularly. The portion generally within the annulus 120 isreferred to as positioned intra-annularly. The portion downstream of theannulus is referred to as being positioned sub-annularly. In theillustrated embodiment, only a part of the foreshortening portion ispositioned intra-annularly or sub-annularly, and the rest of the stent40 is supra-annular.

In the illustrated embodiment, the anterior mitral leaflet 122 has notbeen removed prior to deploying the replacement valve 28. Preferably,the posterior mitral leaflet (not shown) also has not been removed priorto deploying the replacement valve. However, in other embodiments, oneor both of these natural valve leaflets may be removed before deployingthe replacement valve.

As discussed in U.S. Provisional Application No. 61/169,367, FIGS.20A-20C show multiple views of a stent frame 640 and fabric linersub-assembly 632 with an alternative anchor feature 648 configuration.In this embodiment, the anchor features 648 incorporate a bulge featurethat, in the case of atrio-ventricular valve replacement, may helpdirect the native valve leaflets and subvalvular apparatus away from thedistal tips of the anchor features 648 prior to attachment. In addition,the larger radius of curvature between the lower portion 644 of thestent frame 640 and the anchor features 648 that is created by the bulgefeature may help to distribute forces and reduce stress in that region.

FIG. 21 illustrates a lateral, cross-sectional view of the heart showingthe embodiment of the prosthetic heart valve implant 628 positionedbetween the left atrium 112 and the left ventricle 114 with the mitralvalve annulus 120 captured between the transition shoulder 646 on theatrial side and the anchor features 648 on the ventricular side. Theanterior leaflet 122 of the mitral valve is also depicted and specificattention is drawn to the left ventricular outflow tract 126 to showthat it is not obstructed by the presence of the prosthetic heart valveimplant 628.

As shown in U.S. Provisional Application No. 61/169,367, FIGS. 22A and22B show a stent frame, such as stent frame 640, in its pre-expandedcondition after the strut pattern 650 has been laser cut into a tube652. It also highlights the locking loop features 654 on the upper edgeof the stent frame which engage with mating features on a support tubeof the delivery device and are used to maintain control over the implantduring the delivery process and prior to final deployment and release.FIG. 22B shows a flat pattern 650 of the same strut geometry as if thestent frame in FIG. 22A were un-rolled. An expanded version of the samestent frame (with a fabric liner) is also shown in FIG. 22B with thevarious sections of the stent frame numbered and labeled. Section 670indicates the upper tissue valve portion or area of the stent frame.Section 672 shows an optional group of struts for this embodimentintended to provide additional support the transition shoulder, such asshoulder 646, or flare region or section depending on the configuration.Section 674 points out the flare radius and flat lip section. In otherembodiments this would also refer to the transition shoulder. In bothcases, this region of the stent frame is meant to engage the top side ofthe valve annulus. Section 676 is the lower connection portion orsection of the stent frame which provides foreshortening and axialclamping as the stent frame expands radially. Section 678 refers to theanchor features, such as anchor features 648, which can be bent andformed to a variety of configurations after the flat pattern 650 is cut.As shown in the illustrated embodiment, the anchors are bent back withbulge and tip.

With reference next to FIGS. 4A and 4B, another embodiment of a stentframe 140 is illustrated. The stent frame 140 is elongate and hasopposing first and second ends 142, 144. A first circumferential ring164 a comprising undulating struts is arranged adjacent the first end142. A second circumferential ring 164 b of undulating struts isdisposed adjacent the first circumferential ring 164 a. Acircumferential foreshortening ring 184 comprised of interconnectedgenerally diamond-shaped foreshortening cells 186 is disposed generallyadjacent the second end 144. A plurality of longitudinal struts 170extend from the first end 142 toward the second end and terminate at aconnection to corresponding foreshortening cells 186. Preferably, thelongitudinal struts 170 pass through the undulating rings 164 andconnect to apices of the rings 164. Preferably a locking member isformed on each longitudinal strut 170 at the first end 142. In theillustrated embodiment the locking members comprise eyelets 72.

Anchors 190 extend from the foreshortening cells 186 at the second end144 of the stent. In the illustrated embodiment, the anchors are bent soas to be directed generally toward the first end 142 and generallyradially outwardly.

The elongate portion of the stent 140 through which the longitudinalstruts extend is a nonforeshortening portion 150. The elongate portionof the stent made up of the foreshortening cells comprises aforeshortening portion of the stent. An elongate portion of the stentbetween the undulating rings 164 and the foreshortening ring 184 isreferred to as a transition portion 194.

In a manner as discussed above in connection with other embodiments,when the stent 140 is radially compacted, the length of the longitudinalsection will remain substantially constant, but the length of theforeshortening portion will increase. Correspondingly, when radiallyexpanded from a compacted state to the expanded state as shown in FIG.4A, the length of the foreshortening portion will decrease, while thelength of the nonforeshortening portion remains the same.

The stent frame 140 is configured to support a flexible valve bodyhaving valve leaflets so as to provide a prosthetic heart valve implant.Preferably the valve body is disposed on the inside of the stent frame.This specification presents multiple stent frame embodiments, which cansupport valve bodies of multiple shapes and configurations so as toprovide valve implants. For ease of illustration, this specification andassociated drawings will refer to a stent or implant without necessarilydiscussing or showing the valve body. However, it is to be understoodthat valve implants are to include a valve body having leaflets.

In the illustrated embodiment, each of the longitudinal struts bendsradially inwardly in the transition portion 194 between the second ring164 b and the foreshortening ring 184 so as to define a shoulder 192along which the outer diameter of the stent lessens. As such, and asshown in FIG. 4A, the diameter of the stent at the first end 142 isgreater than the diameter of the stent 140 at the second end 144 whenthe stent is in the relaxed position. In the illustrated embodiment, theanchors 190 extend radially outwardly sufficient so that tips of theanchors are disposed diametrically about the same as or outwardly fromthe shoulder. As discussed in U.S. Provisional Application No.61/169,367, the use of the anchor features on the ventricular side ofthe stent frame is intended to maximize the stent frame's ability tocounteract the high pressures that the atrio-ventricular valves willexperience during the systolic portion of the heart's pumping cycle. Thebend configuration of the anchor features in this embodiment isdifferent from that shown previously in FIG. 19 in that it does notincorporate the bulge feature and instead has a smaller radius ofcurvature in the region where the anchor features extend radiallyoutward from the stent frame. A tighter radius in that region isexpected to provide further anchoring strength in the axial direction.In addition, this embodiment does not incorporate the additional supportstruts shown in Section 672 of FIG. 22B.

As discussed in U.S. Provisional Application No. 61/169,367, FIGS. 23A-Dshow a stent frame 740, similar to stent frame 140 of FIG. 4A, with alarger diameter upper portion 742 and a smaller diameter lower portion744 with the valve 730 located solely in the upper portion 742 of thestent frame 740. Of the three embodiments described herein in connectionwith FIGS. 23A-D, 24A-D and 25A-D, this embodiment provides the largestpossible effective orifice area for the valve 730. It also minimizes oreliminates foreshortening in the valve region which may provideadditional durability in the case of tissue valve materials by reducingany tensile forces that could be acting on the tissue as the stent frame740 changes diameter during loading and expansion. As shown in thefigures of U.S. Provisional Application No. 61/169,367, in someembodiments, the upper portion 742 can have a diameter of 38millimeters, the lower portion 744 can have a diameter of 32 millimetersand the valve 730 can have a length of 14 millimeters and be tied to the38 millimeter section sitting in the left atrium.

A variation of this embodiment is shown in FIG. 18 where the stent frameformation 540 and valve 530 location are identical; however in FIG. 18,the height of the valve 530 has been reduced. This allows blood to flowthrough the stent frame 540 and around the delivery device, whichprovides intermediate valve functionality when the implant 528 ispartially deployed.

As further discussed in U.S. Provisional Application No. 61/169,367,FIGS. 24A-D show a same stent frame 740 formation as previouslydescribed in connection with FIGS. 23A-D but with an intra-annular valve730 b position. In this configuration, the valve 730 b is attached tothe lower portion 744 of the stent frame 740 resulting in anintra-annular position. As shown in the figures of U.S. ProvisionalApplication No. 61/169,367, in some embodiments, the upper portion 742can have a diameter of 38 millimeters, the lower portion 744 can have adiameter of 32 millimeters, and the valve 730 b can have a length of 8millimeters and tied to the 32 millimeter section. This design minimizesthe potential for stagnant blood flow and eliminates any low-flowregions within the left atrium, while still maintaining a singlediameter valve.

In a preferred embodiment, the stent frame is initially provided as acircular cross-section nitinol tube. The tube is laser cut according toa pattern corresponding to the struts, cells and the like. The cut tubepreferably is electrochemically polished to as to remove rough edges.The cut and polished nitinol tube may be shaped in accordance with adesired manner, such as shaping the anchors to extend radiallyoutwardly, and the nitinol stent frame may be heated-treated to bothestablish the shape memory and to obtain desired elasticity attributes.

With specific reference to FIG. 5A, a flat pattern for laser cutting anitinol tube to form the stent 140 of FIG. 4A is shown. As indicated,the rings 164 are formed near a first end of the flat pattern and theanchors 190 formed are at an opposite second end of the flat pattern.The rings 164 include the cuts for the undulating struts, and theforeshortening ring 184 includes the cells 186 in a flat configuration.The transition area 194 is shown between the undulating rings 164 andthe foreshortening ring 184. Although the stent is initially cut to thepattern shown in FIG. 5A, further shaping and manipulation is performedto form it into the shape shown in FIG. 4A. For example, the stent as awhole is stretched radially, the anchors 190 are bent backwardly, andthe longitudinal struts 170 in the transition portion are deformed toform the shoulders 192. The stent is then heat treated, as appropriate,so as to take on the illustrated desired shape as its relaxed shape.

As further discussed in U.S. Provisional Application No. 61/169,367,FIGS. 5B and 5C show the flat pattern stent frame geometry withlocations for eyelet holes, 73 a-d, 75 a-d, that will be utilized duringthe assembly process to attach the valve material and the liner materialto the stent frame. FIG. 5B designates potential eyelet locations 73 a-din both the tissue area 77 and the fabric liner area 79 of the stentframe 140. FIG. 5C shows another variation where the eyelet holes 75 a-dhave been incorporated into the flat pattern stent frame geometry.

In the embodiment illustrated in FIG. 4A, there is nooutwardly-extending anchor barb upstream from the anchors 190.Preferably, in practice, the stent 140 is placed so that the valveannulus is captured between the anchors 190 and the shoulder 192. Assuch, the shoulder 192 and anchors 190 cooperate to hold the stent 140in place, preventing the stent from being forced either way through thenative annulus.

With reference next to FIG. 6, another embodiment of a stent 140 a isshown, having structure similar to the stent 140. However, in thetransition portion 194 of stent 140 a, the longitudinal struts 170 bendalong their length to extend radially outwardly, and then bend again toextend radially inwardly so as to define an outward flare 196. In theillustrated embodiment, at least portions of the undulating struts 65 ofthe second undulating ring 164 b take on the curvature of the at leastpart of the flare 196.

In a manner similar to the embodiment of FIG. 4A, the flare portion 196of the transition portion 194 effectually creates a shoulder 192.However, in the stent 140 a embodiment illustrated in FIG. 6, thediameter at the first end 142 of the stent 140 a is substantially thesame as the diameter of the stent at the second end 144. Preferably, andin a manner having similarities to the discussion above, during valvedeployment, the native valve annulus will be captured in the areabetween the anchors 190 and the shoulder 192. In a preferred embodiment,the flat cut pattern as illustrated in FIG. 5A can be formed into theshape of stent 140 a. Thus, multiple stent shapes can be formed from thesame cut pattern.

As discussed in U.S. Provisional Application No. 61/169,367, FIGS. 25A-Dshow a stent frame 840, similar to stent 140 a of FIG. 6, with a smallerdiameter upper portion 842, a central flare 843 to provide thetransition shoulder, and a smaller diameter lower portion 844 (equal tothat of the upper portion 842). Here the upper edge of the valve 830 isattached in the center of the upper portion 842 of the stent frame 840,while the lower edge of the valve 830 and the commissural posts 834 ofthe interior leaflets are attached in the lower portion 844 of the stentframe 840. This configuration maintains a consistent diameter for thevalve 830 while allowing for longer leaflets which could offer improvedhemodynamics by minimizing opening and closing angles of the valveleaflets. As shown in the figures of U.S. Provisional Application No.61/169,367, in some embodiments, the upper portion 842 can have adiameter of 32 millimeters, the outward flare 843 can have a diameter of38 millimeters, the lower portion 844 can have a diameter of 32millimeters, and the valve 830 can have a length of 16 millimeters andbe tied to the upper and lower 32 mm sections.

There are two options shown for possible anchor features that may beadded to the upper section of the stent frame to offer additionalfixation. In the atrio-ventricular position, this would correspond toadditional fixation on the atrial side of the annulus. With reference toFIG. 7A, yet another embodiment of a stent 140 b has a structure muchlike that of stent 140. However, as shown, an upstream anchor 190 bextends from each of the free apices 118 of the second ring 164.Preferably the upstream anchors 190 b extend distally past the initialbend of the shoulder 192. As discussed in U.S. Provisional ApplicationNo. 61/169,367, in an embodiment, the anchor 190 b would extend downwardfrom the supporting struts in the upper section of the stent frame andwould be equally spaced between the contact points of the opposinganchor features extending from the lower portion of the stent frame. Asnoted in U.S. Provisional Application No. 61/169,367, in an embodimentthe contact location would be the same radial distance from the edge ofthe annulus. In this embodiment, during valve deployment, a nativeannulus preferably is captured between and engaged by the anchors 190,shoulders 192 and upstream anchors 190 b. An embodiment of another stent140 d, similar to stent 140 b, is illustrated in FIG. 7B in an expandedstate and FIG. 7C in a collapsed state.

With reference next to FIG. 8A, still another embodiment of a stent 140c having basic structure very similar to stent 140 of FIG. 4A isillustrated. In the illustrated embodiment, the longitudinal struts 170bend in a transition portion 194 so as to define a shoulder 192.However, as shown in the illustrated embodiment, at or near thebeginning of the inward radial bend, the longitudinal struts each splitinto three arms 198 a, 198 b, 190 c. First and second arms 198 a, bcooperate to define a cell which preferably extends the length of theshoulder 192 from the point of bending to a foreshortening cell 186 ofthe foreshortening ring 184. A third arm 190 c between the first andsecond arms 198 a, b extends from the bend portion toward the second end144 of the stent 140 c and radially outwardly so as to define a strutanchor 190 c generally opposing the corresponding downstream anchor 190.As discussed in U.S. Provisional Application No. 61/169,367, in anembodiment, the anchor 190 c would extend outward at the start of thetransition shoulder 192 and would be aligned with the tips of theopposing anchor features extending from the lower portion of the stentframe. As noted in U.S. Provisional Application No. 61/169,367, in anembodiment the contact location would be the same radial distance fromthe edge of the annulus. In a manner similar to other embodimentsdiscussed above, during valve placement, preferably a native valveannulus is captured in the space between the downstream anchor 190 andthe strut anchor 190 c. The stent 140 c is held securely in place by theopposing anchors 190, 190 c, and shoulder 192. An embodiment of anotherstent 140 e, similar to stent 140 c, is illustrated in FIG. 8B in anexpanded state and FIG. 8C in a collapsed state.

In the embodiments discussed above, stent frames have been described inwhich upstream end of the stent has a diameter greater than a downstreamend of the stent, and embodiments have been described in which theupstream and downstream ends have substantially the same diameter. It isalso to be understood that other stent embodiments may have a downstreamend having a greater diameter than an associated upstream end.

In the stent frame embodiments discussed above, the stents are cut froma tube having similarities to the embodiment shown in FIG. 5A, and theanchors are formed during processing by bending the anchor portionsbackwardly and radially outwardly. It should be understood that aplurality of anchor shapes may be employed as desired. For example, withreference next to FIG. 9A, one embodiment of an anchor 90 a comprises arelatively large base radius having a generally “U”-shaped bend. FIG. 9Bshows an anchor 90 b also having a relatively large base radius but thencontinuing bending about the radius beyond 180° so as to define a bulgedfeature before bending again so as to extend toward the first end of thestent. FIG. 9C presents an anchor 90 c having a relatively tight baseradius leading to an outward bend and then another bend back inwardly sothat the anchor tip is directed generally parallel to or slightlyoutwardly from a longitudinal axis of the stent. FIG. 9D illustrates ananchor 90 d with a relatively large base radius leading to an outwardbend before bending back inwardly so that the anchor tip is directedgenerally parallel to or slightly outwardly from a longitudinal axis ofthe stent. FIG. 9E shows an anchor 90 e having a tight base radius thatcompletes only about a 130°-160° turn, and then continues to curveslightly along its length having a very long bending radius so as toapproach, but not necessarily complete, a 180° turn at its tip.

In the illustrated embodiment, the tips of the anchors have been shownas generally pointed or flat. It is to be understood that numerous tipconfigurations can be employed as desired to optimize the engagement andattachment of the replacement heart valve to the native valve annulus.For example, FIG. 10a shows an anchor tip 92 a having a smooth radiusconfigured to limit trauma to the tissue. FIG. 10b illustrates anembodiment of an anchor tip 92 b having an expanded ball radius. Such aball radius can be created as a two-dimensional circular shape duringthe laser cutting process, or can be a three-dimensional sphere attachedto the anchor tip during, for example, a ball welding procedure. FIG.10c shows a pointed anchor tip 92 c configured to provide some degree ofpenetration into the tissue of the valve annulus. FIG. 10d illustrates aflared anchor tip 90 d configured to distribute anchor forces over asurface area of tissue, but also comprising a serrated edge topenetratingly engage such tissue. In additional embodiments a flared tipmay have a smooth edge. Additionally, further tip configurations can beemployed as desired to optimize engagement and fixation for differentvalves and different disease morphologies. In further embodiments, asnoted in Provisional Application No. 61/169,367 different tipconfigurations can be combined within a single stent frame to furtheroptimize engagement and fixation as needed.

The embodiments as disclosed above in connection with replacement heartvalves can be delivered to a patient's heart valve annulus in variousways, such as by open surgery, minimally-invasive surgery, andpercutaneous, or transcatheter, delivery through the patient'svasculature. With reference next to FIGS. 11A and 11B, an embodiment ofa delivery device 200 is shown in connection with a replacement heartvalve. The illustrated embodiment comprises an elongate, steerabledelivery catheter configured to be advanced through a patient'svasculature in a percutaneous delivery approach. The illustrated device200 comprises an elongate inner tube 202 that is attached at its distalend to a nose cone 204. The inner tube 202 has a lumen sized andconfigured to slidably accommodate a guidewire 206 so that the device200 can be advanced over the guidewire 206 through the vasculature. Asupport tube 208 concentrically encircles the inner tube 202 and issized to be slidable over the inner tube. An outer sheath 210 isdisposed so as to be slidable over the support tube 208. In theillustrated embodiment, and preferably, in a manner as discussed inembodiments presented below, the support tube 208 and outer sheath 210cooperate to grasp onto an end of the replacement heart valve, which,for ease of illustration, is here represented by showing only a stentframe. For delivery, the valve is compacted and held within the outersheath 210. As noted in Provisional Application No. 61/169,367, thedevice shown here represents a percutaneous or trans-catheter embodimentof the delivery device. In a surgical or minimally-invasive embodiment,the components would remain the same, however, the overall length of thesystem would be shorter and flexibility of the sheath and tubecomponents may or may not be required.

With reference next to FIGS. 12 and 13, delivery device 220 configuredin accordance of one embodiment is shown at various steps along asequence or method of valve implant deployment. More specifically, FIGS.12A-12I demonstrate schematic views of various steps of a deploymentprocess, and FIGS. 13A-13C show the state of the delivery device 220relative to a native heart valve annulus 120 at certain stages ofdeployment. In the embodiment illustrated in FIG. 13, the deploymentdevice 220 deploys the heart valve implant 222 into a patient's nativemitral annulus 120. It is to be understood, however, that features andaspects as discussed herein may be employed when employing valveselsewhere in a patient's heart or other vasculature.

With specific reference to FIG. 13A, in use preferably the deliverydevice 220 is advanced into the patient's heart 110 so that a distal endincluding a nose cone 224 passes through the diseased native valve andthrough the native annulus 120. As such, the delivery device 220preferably is positioned so that the anchor portions 226 of the valveimplant 222, though still compacted within an outer sheath 230, aredisposed generally on a side of the native annulus opposite an approachdirection. Once the delivery device 220 is in place, and as nextdepicted in FIG. 12A, the outer sheath 230 begins to be retractedthereby exposing the distal, or anchor end 232, of the valve implant222. In the illustrated embodiment, barb-shaped anchors 226 are disposedat the anchor end 232. It is to be understood that other embodiments mayemploy other anchor structures. As the outer sheath 230 continues to beretracted as shown in FIG. 12B, more of the stent 222 is exposed and theanchor end of the stent begins to expand radially as progressively shownin FIGS. 12B, C and D. However, and as more particularly shown in FIG.12D, a proximal end 234 of the stent frame 222 is still held securelywithin the outer sheath 230, preferably by the outer sheath cooperatingwith a support tube so as to restrain the proximal end 234 of the stent222 from being released from the delivery device 220. Nevertheless,since the distal portion 232 of the stent has been substantiallyreleased it is free to expand and, in the embodiment shown in FIG. 12D,the distal end 232 of the stent can expand to its fully expanded statewhile the proximal end of the stent remains restrained within the outersheath.

With additional reference now to FIG. 13B, when the distal end 232 isfully expanded a slight back pressure preferably is applied to theentire delivery device 220 so as to pull the stent 222 proximally andseat the implant 222 and particularly the anchor features 226, againstthe native annulus. In the illustrated embodiment, the anchor features226 are seated against the subvalvular side of the initial annulus 120.Proper seating of the implant can be confirmed via tactile feedback,external imaging, and/or other suitable methods.

With continued reference to FIGS. 12 and 13, if, for example, dataindicates that the placement of the stent frame 222 should be modified,such as due to improper seating, alignment, engagement or the like. Theimplant 222 can be at least partially resheathed and repositioned. Forexample, with particular reference to FIGS. 12E and 12F, since theimplant has not been fully deployed from the outer sheath 230, the outersheath 230 can be moved distally, thus engaging and compacting the stentframe so as to force it back into the outer sheath. Such compaction willremove the implant 222 from its faulty positioning. The implant can thenbe repositioned and redeployed in a new position by again moving theouter sheath 230 proximally as depicted in FIG. 12G.

Once it is determined that the implant 222 is correctly seated, with theanchors 226 disposed as desired in the subvalvular side of a nativeannulus, the implant can be completely released from the delivery device220. Preferably, and with reference next to FIG. 12H, such completerelease comes when the outer sheath 230 continues to be retractedproximally, exposing the proximal end 230 of the stent frame 222 anddisengaging the locking mechanism between the stent frame, support tubeand outer sheath. As such, the entire stent becomes free of anyconstraint by the delivery device and expands freely as depicted inFIGS. 12I and 13C so that the implant is fully deployed at the nativeannulus.

As shown in FIG. 13C, preferably a foreshortening portion of the stent222 is generally aligned with the native annulus 120 so that the annulusis captured between the anchor features 226 and an opposing anchorfeature such as a shoulder portion of the stent. Of course, in otherembodiments, other configurations of anchoring portions may or may notinclude a shoulder, may include upstream and downstream anchors, and/ormay include other structure for engaging one or both sides of anannulus. Once the implant is fully deployed, preferably the sheath isagain moved distally to re-engage the nose cone, and the delivery deviceis removed from the patient.

In the embodiment discussed and illustrated in connection with FIGS. 12and 13, only a distal portion of the delivery device 220 is shown. It isto be understood that such a distal portion may be employed in multipledelivery device configurations. For example, a percutaneous,transcatheter-approach delivery device such as shown in FIGS. 11A and11B can employ a distal portion similar to that in the embodiment shownin FIGS. 12 and 13. Also, delivery devices for us in minimally-invasiveor even open surgical procedures may have similar structure and similaroperation principles although such devices may advantageously have somedifferent mechanical properties such as increased stiffness, than doembodiments used in trans-catheter approaches.

With reference next to FIGS. 14A-14L, an embodiment of a delivery device238 and a method and apparatus for loading a heart valve implant 128onto the delivery device is shown. With reference first to FIG. 14A, theloading apparatus comprises a compacting device 240 which, in theillustrated embodiment, is generally funnel-shaped. The funnel 240 iselongate and comprises a first and second end 242, 244. The first end242 has a comparatively large diameter and the second end 244 has acomparatively small diameter. A transition 246 progressively decreasesthe diameter between the first and second ends. Preferably, an elongatecompaction portion 250 is disposed at and adjacent second end 244.Preferably, the diameter within the compacted portion 250 is generallyconstant along its length and approaches or matches the diameter of thesecond end 244.

A cap 252 is provided and is shaped to fit through the first or largeend 242 of the funnel 240. Preferably an outer surface of the cap 252 isconfigured to fit generally complementarily against the inner surface ofthe funnel 240. A first end 254 of the cap 252 is configured to fitgenerally onto and hook onto the first end 242 of the funnel. A secondend 256 of the cap 252 is configured to fit within the funnel andpreferably proximal of the compacting portion 250 of the funnel 240. Thesecond end of the cap preferably comprises a blocking structure.

With continued reference to FIG. 14A, an example heart valve 128 isshown. In the illustrated embodiment, the heart valve comprises thestent frame 140 described above in connection with FIG. 4A. To aid insimplicity of illustration, only the stent frame, and not the valvebody, is shown. It is to be understood, however, that in practicepreferably a completely assembled heart valve implant is employed.Additionally, it is to be understood that implants and stents havingconfigurations other than the specifically shown implant can make use ofa compacting apparatus and delivery device having features in accordancewith the features and principles discussed in connection with thisembodiment. However, this structure and method are particularlypreferred in connection with implants having self-expanding stents.

As shown in FIG. 14A, preferably, the first end 242 of the funnel 240has a diameter large enough to accommodate the fully expanded, at reststent frame 140. Further, preferably, the stent frame is positioned sothat its first end 142, at which the locking members 72 are disposed, isfacing toward the funnel. In the illustrated embodiment, the lockingmembers comprise eyelets. Other structures may be employed in otherembodiments.

A pull member 260 or “octopus” preferably comprises a pull ring 262 thatis connected to a plurality of elongate arms 264. Each of the armspreferably terminates in a hook 266 or other securing member that isconfigured to engage one of the locking members/eyelets 72. Preferably,there are the same number of arms 264 as there are eyelets 72.Additionally, preferably the arms are substantially flexible so as toappropriately distribute forces and to obtain secure purchase on thestent frame. In one embodiment, the arms 264 comprise a suture material,although various types of string and even semi-rigid plastics, wires orthe like may be employed.

With additional reference to FIG. 14B, an O-ring 270 is preferablydisposed about the compacting portion 250 of the funnel 240 andgenerally adjacent the second end 244 of the funnel. In the illustratedembodiment, the O-ring 270 is an inwardly biased broken ring shapehaving a pair of tabs 272 adjacent the break in the ring. The tabsassist in placing the ring over the compacting portion 250 of the funneland other side manipulating the O-ring. Preferably, the O-ring 270 isconfigured so that its at-rest position is at a diameter substantiallyless than the diameter of the compaction portion.

With reference next to FIG. 14C, in operation preferably the octopusarms 264 are threaded through the open second end 244 of the funnel, outthe first end 242 of the funnel, and engaged with the implant 128 sothat each octopus hook 266 connects to one of the eyelets 72, on thestent frame 140. The pull ring 262 is then pulled so as to pull theimplant into and through the first end of the funnel. As the pull ringcontinues to be pulled distally, the stent engages the inner surface ofthe funnel at the transition 246 and is forced to be radially compactedas the stent 140 is pulled through the funnel 240 until it issubstantially compacted within the compaction portion 250 of the funneland with the locking members 72 of the stent frame extending out of thesecond end of the funnel as shown in FIG. 14D.

With continued reference to FIG. 14D, once the implant has been pulledinto the compaction portion 250 of the funnel so that the locking memberportions of the frame are exposed and extend out of the second end ofthe funnel, the cap 252 preferably is inserted through the first end ofthe funnel so that its second end 256 is generally adjacent the secondend 144 of the stent frame. The blocking structure at the second end ofthe cap 252 preferably is configured to prevent the stent frame frommoving backwards out of the funnel. For example, the cap may have athickness that substantially blocks such backwards movement. Otherstructures such as partial or full blocking of the funnel may also beemployed. With the cap in place, the octopus arms are disengaged fromthe locking members as shown in FIG. 14E.

With reference next to FIG. 14F, additional structure of the deliverydevice is illustrated in connection with the funnel 240 and implant 128in the configuration of FIG. 15E. As shown, the delivery device 238comprises an elongate inner tube 274 that is connected to a nose cone276. Preferably, the inner tube 274 has a lumen sized and adapted toaccommodate a standard guidewire 278 extending therethrough. The nosecone 276 preferably has a generally atraumatic tip portion 280 at itsdistal end and has a cavity 282 formed in its proximal end. Acircumferential skirt 284 extends from the proximal end of the nose cone276 and an inner surface 286 of the circumferential skirt 284 definesthe cavity 282.

An elongate support tube 290 has a lumen sized and configured toslidably accept and slide over the inner tube 274. A locking mechanism292 comprising a plurality of locking features 294 is disposed adjacenta distal end of the support tube 290. In the illustrated embodiment, thelocking features comprise bosses 294 extending radially outwardly froman outer surface of the support tube. The illustrated bosses 294 aresized and shaped to generally matingly fit the eyelets of the stentframe 140.

An outer sheath 300 is configured to fit slidably over the support tube290. The outer sheath 300 has a thickness defined between an outersurface 302 and an inner surface 304. A diameter of a lumen of the outersheath is defined by the inner surface 304 and preferably the lumendiameter 75 such that the inner surface just clears the locking bosses294 of the support tube, as will be discussed and shown in more detailbelow. A raised portion 306 of the outer sheath 300 is disposed near butspaced from a distal end of the outer sheath, and a seat 308 is definedon the distal end of the raised portion 306. As will be discussed inmore detail below, the raised portion and seat 308 are configured toengage a proximal end of the nose cone circumferential skirt 284.

Although the delivery device has just been introduced in connection withFIG. 14F, it is to be understood that, in some embodiments, the funnelis threaded over the delivery device so that the funnel concentricallysurrounds the inner tube and is disposed between the nose cone and thesupport tube before the heart valve implant is loaded into the funnel.Thus, in some embodiments, preferably the heart valve is loaded into andcompacted within the funnel while the funnel is already disposed overthe inner tube of the delivery device.

With reference next to FIG. 14G, with the implant loaded into thecompaction portion of the funnel, the support tube 290 preferably isadvanced distally so that the eyelets 72 of the implant 140 aregenerally aligned with the bosses 294 of the support tube. However, inthe illustrated embodiment, the diameter of the compaction portion 250of the funnel is greater than the diameter of the support tube 290, andthus the eyelets 72 are disposed radially outwardly from the bosses 294.With reference next to FIG. 14H, preferably the inwardly biased O-ring270 is slipped off of the end of the funnel and onto the exposedconnecting portions of the stent frame so as to urge the eyeletsinwardly and into engagement with the aligned bosses. The implant isthus connected to the support tube 220.

With reference next to FIG. 14I, with the eyelets 72 and bosses 294engaged, the outer sheath is then advanced distally over the supporttube 290 so that the distal end of the outer sheath extends over anddistally past the bosses. As discussed above, the lumen diameter of theouter sheath is chosen so that the inner surface 304 just clears thebosses 294 of the support tube. Thus, when the outer sheath is moveddistally past the bosses when the bosses are engaged with the eyelets72, the eyelets are captured between the outer sheath 300 and supporttube 290, and the first end of the stent is securely held by the supporttube. With the eyelets now fully captured, the O-ring is removed.

With reference next to FIG. 14J, the outer sheath 300 continues to bemoved distally relative to the support tube 290 and attached implant140. In the illustrated embodiment, the outer sheath inner diameter isless than the diameter of the funnel compaction portion. Thus, as theouter sheath is moved distally, it progressively radially compacts theheart valve implant. As the implant is progressively compacted withinthe outer sheath, the funnel 240 preferably is also moved distally sothat the implant is progressively transferred from being containedwithin the funnel to being contained within the outer sheath 300.Eventually, the funnel is completely removed from the implant and theouter sheath contains the implant from its first to its second end, asshown in FIG. 14K.

In the embodiment illustrated in FIG. 14K, the stent frame 140 of theimplant has anchors 190 extending radially outward at the second end144. Those anchors are not captured within the outer sheath in thisembodiment, although the outer sheath preferably captures substantiallythe rest of the stent frame therewithin.

With the implant captured in the outer sheath, the funnel preferably canbe removed from the delivery device. In the illustrated embodiment, thesmallest diameter portion of the funnel is greater than the outerdiameter of the nose cone. Thus, the funnel can be removed by moving itdistally over the nose cone. In other embodiments, the funnel may have alesser diameter than the nose cone, and can be moved by other means suchas by cutting the funnel. In still other embodiments, the funnel canhave a multiple piece and/or hinged construction and may be held closedby a releasable clamp, clip, or the like. As such, once it has servedits purpose and the implant is transferred to the outer sheath, thefunnel can be disassembled and/or opened and removed without necessarilydrawing the funnel over the nose cone.

With reference next to FIGS. 14K and 14L, with the funnel removed andthe implant substantially captured within the outer sheath 300, the nosecone 276 is pulled proximally until as shown in FIG. 14L, the skirtportion 284 of the nose cone engages and compacts the anchors 190, andeventually the proximal end of the nose cone skirt engages the seats 308defined on the raised portion of the outer sheath. The anchors 190 arethus secured between the nose cone skirt inner surface 286 and the outersheath outer surface 302. The implant is thus fully contained within thedelivery device 238 which preferably maintains a substantiallycontiguous outer surface. The implant may be delivered to a native heartvalve annulus in a manner having similarities to the embodimentdiscussed above in connection with the FIGS. 12 and 13.

In the embodiment discussed above in connection with FIG. 14, the nosecone 276 is depicted as rigidly attached to the inner tube 274. Inanother embodiment, the nose cone may be selectively detachable from theinner tube so that the valve implant can be independently drawn into afunnel compaction apparatus, without the funnel being mounted over thedelivery device. Thus, a loaded funnel as depicted in FIG. 14E can beadvanced over an inner tube, and then the nose cone may be attached tothe inner tube. In such an embodiment, the funnel may have a smallerdiameter than as shown and discussed above, as the funnel is notnecessarily of large enough diameter to be drawn over the nose cone, andinstead the nose cone may be removed in order to remove the funnel. Infact, in such an embodiment and in some options of such an embodiment,the nose cone is not attached to the inner tube until after the funnelis removed and the implant is substantially captured within the outersheath.

With reference next to FIGS. 15A-H further embodiments of a device forloading a heart valve implant 128 onto a delivery device 238 are shown.For ease of illustration, the same implant 128/stent frame 140 used inconnection with the embodiment described in FIG. 14 is employed, as wellas other similar structures, such as the pull member 260, and deliverydevice 238 structure such as the inner tube 274, nose cone 278, supporttube 290 and outer sheath 300.

With particular reference to FIG. 15A, the illustrated embodimentcomprises a two-piece compaction device 310 comprising a funnel portion315 and a loading tube portion 320. Preferably, the funnel portion 315and the loading tube portion are detachably connected to one another.Further, preferably the loading tube portion 320 is elongate and has asubstantially constant diameter. As with other embodiments, preferablythe octopus arms 264 of the pull member 260 extend through thecompaction device 310 to hook onto and engage portions of the implant128, 140. In the illustrated embodiment, the hooks 266 engage the stent140 at the second end 144 of the stent.

In practice, the pull ring 262 is pulled so as to pull the stent intothe compaction device and through the funnel portion 315 to radiallycompact the stent 140. Preferably, however, a loading inner tube 328 isarranged concentrically within the stent 140 as it is being compacted.As shown in FIG. 15B, the implant 128, 140 eventually is radiallycompacted within the loading tube 320 and concentrically surrounding theloading inner tube 328. As shown in FIG. 15B, preferably the loadingtube 320 has a length that is somewhat less than the total length of thestent 140 when the stent is in its compacted arrangement. As such, atleast the eyelets 72 of the first end 142 extend beyond an end of theloading tube 320.

With reference next to FIG. 15C, once the implant 128 is compactedwithin the loading tube 320, the pull member 260 may be detached fromthe implant and the loading tube may be detached from the funnel portion315 so that the loading tube end associated compacted stent 140 andinner loading tube 328 can be independently moved and manipulated.

FIG. 15C shows an embodiment in which the delivery device 238 isconfigured so that the nose cone 276 can be releasably detached from theinner tube 274. Preferably, the inner loading tube 328 defines an innerlumen having a diameter greater than the outer diameter of the innertube 274 so that the inner loading tube can be threaded over the innertube so as to place the compacted implant 128, 140 on the deliverydevice 238 between the nose cone 276 and the support tube 290. Inanother embodiment, the nose cone is not detachable from the inner tube.Thus, in order to get the compacted implant disposed on the deliverydevice 238, the implant is threaded onto the inner tube 274 before thesupport tube 290 and outer sheath 300 are threaded over the inner tube274.

In either case, however, once the support tube 320 with its accompanyingcompacted implant are threaded over the inner tube 274 as desired, theinner loading tube preferably is removed from within the compactedimplant and removed from the delivery device. For example, in theembodiment illustrated in FIG. 15C, the loading inner tube 328 can beremoved distally off the end of the inner tube 274 when the nose cone276 is detached. In other embodiments, the loading inner tube 328 can beslid off of the inner tube 274 before the support tube 290 and outersheath 300 are advanced over the inner tube 274. As such, and as shownin FIG. 15B, the loading tube 320 with its attendant compacted implant128, 140 is disposed on the inner tube 274 between the nose cone 276 andthe support tube 290.

With reference next to FIGS. 15E-15H, preferably the delivery device 238is then manipulated and operated in a manner similar to that asdiscussed above in connection with FIGS. 14G-K so as to capture thefirst end 142, and more specifically the eyelets 72, of the stent frame140 within the outer sheath 300 using a method of apparatus includingthe support tube 290 and bosses 294, although other configurations oflocking mechanisms 292 may be employed as desired.

With specific reference next to FIG. 15G, in one embodiment, after theimplant has been captured within the outer sheath 300, the loading tubeportion 320 preferably is removed from around the delivery device 238.In the embodiment illustrated in FIG. 15G, the loading tube 320 can bemoved proximally over the outer sheath 300 as the outer sheath engagesthe nose cone 276. In the embodiment illustrated in FIG. 15H, theloading tube 320 is advanced distally so as to be removed over the nosecone 276 as the outer sheath also is distally to engage the nose cone276.

In the illustrated embodiments, the loading tube 320 has a lumendiameter sufficiently large so that it can be removed over the nose cone276, or at least clear the raised portions 306 of the outer sheath 300.In other embodiments, however, the loading tube may have a lumendiameter more closely approaching the inner diameter of the outer sheathlumen. Removal of the loading tube 320 after the implant is sheathedwithin the outer sheath 300 may involve breaking or cutting the loadingtube 320 or, in other embodiments, the loading tube comprises multiplepieces that can be disassembled or opened so as to remove the tube fromthe delivery device 238.

In one of the embodiments discussed above, the nose cone is detachablefrom the inner tube. It should be understood that, in one suchembodiment, the nose cone is not reattached to the inner tube untilafter the compacted stent is at least partially pulled into the outersheath, and the loading tube is removed from the delivery device 238. Assuch, in this embodiment, the loading tube can have a lumen diameterless than an outer diameter of other structures of the delivery device.

In the embodiments discussed above, an inwardly-biased O-ring 270 isemployed to urge locking members 72 of the stent into engagement withlocking bosses 294 of the support tube 290. It is to be understood,however, that other methods and structures can be employed to engage thelocking members of the stent with the support tube. For example, a usercan manually urge the locking members into engagement with the bosses.Additionally, other structures, such as a belt, specially-configuredclamping pliers, or the like can be employed to urge the locking membersinto engagement with one another. It is contemplated that yet furtherstructures can be employed for this purpose.

With reference next to FIGS. 16A and 16B, another embodiment of amulti-piece compaction device 410 comprises a funnel portion 415 and anelongate load tube 420 that are detachably connected to one another. Thefunnel portion and load tube preferably share at least some featureswith other embodiments discussed in this specification. In theillustrated embodiment, the smaller end of the funnel portion comprisesan L-lock track 417 formed therein. The load tube 420 comprises anoverlap portion 422 having a lock member 424. A diameter of the overlapportion 422 is reduced so that the overlap portion will fit within theend of the funnel portion 415 at the L-lock track 417. The lock member424 is slidable within the track 417 so as to detachably secure thefunnel portion 415 and load tube 420 together. It is to be understoodthat other structures can be employed to detachably connect the funneland load tube.

With reference next to FIGS. 17A-G, in another embodiment, an implant400 is provided in which longitudinal struts 406 terminate in lockingmember 404 at a non-anchoring end of the stent 400. The illustratedlocking members 404 have a generally arrowhead-type shape that isenlarged relative to the adjacent strut 406. Preferably a pull member260 a engages the stent 400 and pulls it through the compaction device410 so that the implant 400 is compacted within the load tube 420. Theload tube and implant can then be removed from the pull member 260 a andfunnel portion 415 and loaded onto an inner tube 274 a of a deliverydevice.

With particular reference to FIG. 17B, the delivery device preferablyincludes the inner tube 274 a, which is attached to a nose cone 276 a. Asupport tube 430 is slidably disposed over the inner tube, and an outersheath 300 a is slidably disposed over the inner tube. Preferably aninner lumen diameter of the outer sheath 300 a is greater than, but veryclose to, an outer diameter of the support tube 430. A locking mechanism432 is provided at the distal end of the support tube 430. The lockingmechanism 432 preferably comprises a tapered surface 434 that leads to acircumferential capture slot 440. A plurality of guide slots 444 areprovided and configured to generally align with struts 406 of theimplant 400. Preferably, the load tube 420 is sized such that theradially compacted implant 400 has an outer diameter less than an outerdiameter of a proximal ridge of the tapered surface 434 immediatelyadjacent the capture slot 440.

To load the compacted implant 400, the support tube 430 is advanced sothat the tapered surface 434 engages and deflects the locking members404 and associated struts 406 of the implant 400, as shown in FIG. 17C.The support tube 430 continues to be advanced until the deflectedlocking members 404 clear the proximal edge of the tapered surface 434,at which point the locking members 404 are no longer deflected, and willspring into the capture slot 440, preferably with an audible “click”.When properly aligned, the struts 406 correspondingly spring into theguide slots 444 as depicted in FIG. 17D, and the stent 400 and supporttube 430 are now engaged.

With reference next to FIG. 17E, the outer sheath 300 a is next advanceddistally so as to cover the capture slot 440 and thus securely capturethe locking members 404 within the sheath 300 a. As the sheath 300 acontinues to be advance distally, the compacted implant is transferredfrom the load tube 420 to the sheath 300 a. Preferably a distal end ofthe sheath engages an end of the load tube 420 during such advancement,and thus anchor members that may in some embodiments be biased radiallyoutwardly can be effectively transferred from within the load tube 420to within the sheath 300 a.

With additional reference to FIG. 17F, preferably the nose cone 276 a issized so that the load tube 420 can be slid thereover and removed fromthe delivery device. In the illustrated embodiment the distal end of thesheath 300 a at least partially overlaps the nose cone, and the sheathis shaped to provide a smooth transition from the distal end of thesheath to the nose cone. Of course, other embodiments may employ otherstructural interaction between the outer sheath and the nose cone, whichmay in some embodiments be removable.

In practice, the illustrated delivery device has operational featuresthat may be similar to other embodiments discussed herein. For example,the implant can be partially deployed, but resheathed for repositioning.If necessary, the implant can also be resheathed for removal from thepatient. In some such embodiments, in the event of complete resheathing,radially-outwardly-biased anchor members may not be able to becompletely recaptured within the outer sheath 300 a in the same positionas originally provided. However, continued advancement of the sheath 300a after engagement of the anchor can have the effect of bending theanchor backwardly (distally) so that it is effectively captured betweenthe sheath and nose cone. The delivery device can then be furthermanipulated, and even removed from the patient, with the entire implant,including anchor portions, fully resheathed.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalentsthereof. In addition, while a number of variations of the invention havebeen shown and described in detail, other modifications, which arewithin the scope of this invention, will be readily apparent to those ofskill in the art based upon this disclosure. In fact, the embodimentsspecifically disclosed herein have been used as a vehicle to describecertain inventive features that can be employed alone or in variouscombinations in multiple additional embodiments. Thus, it iscontemplated that various combinations or subcombinations of thespecific features and aspects of the embodiments may be made and stillfall within the scope of the invention. For example, support tubeembodiments such as in FIG. 14 can be modified to capture lockingmembers within a capture slot as disclosed in FIG. 17, and vice versa.Further, even though the stents described herein have been configured toforeshorten, certain features such as the methods and apparatus forcontrolled delivery as discussed in connection with FIGS. 12 and 13, canbe employed with self-expanding stents that don't necessarilyforeshorten, and don't necessarily have anchoring features comparable tothe embodiments disclosed herein. Further, the delivery device depictedin FIGS. 12 and 13 can be replaced with delivery devices employingprinciples as discussed in FIG. 14, 15, 17 or the like. Accordingly, itshould be understood that various features and aspects of the disclosedembodiments can be combined with or substituted for one another in orderto form varying modes of the disclosed invention. Thus, it is intendedthat the scope of the present invention herein disclosed should not belimited by the particular disclosed embodiments described above, butshould be determined only by a fair reading of the claims that follow.

What is claimed is:
 1. A replacement mitral valve configured to bedelivered to a native mitral valve and secured relative to a nativemitral valve annulus, the native mitral valve positioned between a leftatrium and a left ventricle, the replacement mitral valve comprising: anexpandable frame comprising a proximal end and a distal end and having alongitudinal axis extending between the proximal end and the distal end,the expandable frame configured to radially expand and contract fordeployment within the native mitral valve; a first anchoring portionconfigured to at least partially engage an atrial side of the nativemitral valve annulus, the first anchoring portion comprising a pluralityof circumferentially-spaced tips connected by at least one row ofcircumferentially expansible elements extending continuously around thefirst anchoring portion, wherein when the expandable frame is in anexpanded configuration, the first anchoring portion extends radiallyoutwardly from a portion of the expandable frame that has a firstcross-sectional dimension such that the at least one row ofcircumferentially expansible elements has a second cross-sectionaldimension greater than the first cross-sectional dimension; a secondanchoring portion distal to the first anchoring portion and comprising aplurality of anchors extending from the expandable frame configured forplacement on a ventricular side of the native mitral valve annulus,wherein when the expandable frame is in an expanded configuration, theplurality of anchors extend at least partially proximally toward thefirst anchoring portion; and a valve body connected to the expandableframe; wherein radial expansion of the expandable frame causes the firstanchoring portion and the second anchoring portion to draw closertogether; and wherein, when the expandable frame is in the expandedconfiguration, tips of the plurality of anchors of the second anchoringportion extend to a third cross-sectional dimension which is at leastabout the same as the second cross-sectional dimension.
 2. Thereplacement mitral valve of claim 1, wherein the plurality of anchoringtips of the first anchoring portion extend radially outward when theexpandable frame is in an expanded configuration.
 3. The replacementmitral valve of claim 1, wherein the plurality of tips of the firstanchoring portion extend generally distally when the expandable frame isin an expanded configuration.
 4. The replacement mitral valve of claim1, wherein the first anchoring portion extends radially outwardly fromthe portion of the expandable frame having the first cross-sectionaldimension in a direction generally perpendicular to the longitudinalaxis.
 5. The replacement mitral valve of claim 1, wherein when theexpandable frame is in an expanded configuration, the expandable framehas a substantially constant outer diameter from where the plurality ofanchors of the second anchoring portion connect to the expandable frameto where the first anchoring portion extends radially outwardly from theportion of the expandable frame having the first cross-sectionaldimension.
 6. The replacement mitral valve of claim 1, wherein theplurality of anchors of the second anchoring portion extend from aforeshortening portion of the expandable frame.
 7. The replacementmitral valve of claim 1, wherein the first anchoring portion comprises anon-foreshortening portion that does not substantially foreshorten whenthe expandable frame radially expands.
 8. The replacement mitral valveof claim 1, wherein when the expandable frame is in an expandedconfiguration, the plurality of anchors of the second anchoring portionextend substantially parallel to the longitudinal axis of the expandableframe toward the first anchoring portion.
 9. The replacement mitralvalve of claim 1, wherein when the expandable frame is in an expandedconfiguration, the plurality of anchors of the second anchoring portionextend distally away from the distal end of the expandable frame andthen extend proximally toward the proximal end of the expandable frame.10. The replacement mitral valve of claim 1, wherein the plurality ofanchors of the second anchoring portion are atraumatic.
 11. Thereplacement mitral valve of claim 1, wherein the at least one row ofcircumferentially expansible elements are arranged in a zig-zag pattern.12. The replacement mitral valve of claim 1, wherein the replacementmitral valve is shaped such that, after the replacement mitral valve hasbeen delivered to the native mitral valve and expanded, at least aportion of the first anchoring portion contacts tissue on the atrialside of the native mitral valve annulus and at least a portion of thesecond anchoring portion contacts tissue on the ventricular side of thenative mitral valve annulus.
 13. The replacement mitral valve of claim1, wherein the expandable frame comprises a D-shaped cross-section. 14.A replacement mitral valve configured to be delivered to a native mitralvalve and secured relative to a native mitral valve annulus, the nativemitral valve positioned between a left atrium and a left ventricle, thereplacement mitral valve comprising: an expandable frame extending alonga longitudinal axis between a first end and a second end, the expandableframe comprising a first portion and a second portion, the first portionbeing closer to the first end than the second portion is to the firstend, and the second portion being closer to the second end than thefirst portion is to the second end, wherein the second portion comprisesa plurality of foreshortening cells and the first portion comprises aplurality of struts having at least a portion thereof extendinglongitudinally from foreshortening cells of the second portion towardthe first end of the expandable frame, wherein the first portioncomprises a non-foreshortening portion that does not substantiallyforeshorten when the expandable frame is radially expanded; a pluralityof anchors connected to the second portion of the expandable frame,wherein the plurality of anchors extend radially outward from theexpandable frame and extend in a direction generally toward the firstend when the expandable frame is in an expanded configuration; and avalve body attached to the expandable frame; wherein when the expandableframe is in an expanded configuration, the first portion comprises ananchoring portion configured to engage an atrial side of the nativemitral valve annulus that extends radially outwardly from the secondportion in a direction generally perpendicular to the longitudinal axis,and wherein the replacement mitral valve is shaped such that, after thereplacement mitral valve has been delivered to the native mitral valveand expanded, at least a portion of the anchoring portion contactstissue on the atrial side of the native mitral valve annulus and atleast some of the plurality of anchors contact tissue on the ventricularside of the native mitral valve annulus.
 15. The replacement mitralvalve of claim 14, wherein the first portion comprises a plurality ofanchoring tips configured to engage the valve on an atrial side of thenative mitral valve annulus when the expandable frame is in an expandedconfiguration.
 16. The replacement mitral valve of claim 14, wherein thefirst portion comprises at least one row of circumferentially expansibleelements, and wherein the struts extend transversely across the at leastone row.
 17. The replacement mitral valve of claim 14, wherein theplurality of anchors are atraumatic.
 18. The replacement mitral valve ofclaim 14, wherein when the expandable frame is in an expandedconfiguration, each of the struts lies in a plane parallel to andintersecting the longitudinal axis.
 19. The replacement mitral valve ofclaim 14, wherein when the expandable frame is in an expandedconfiguration, the first portion of the expandable frame has across-sectional dimension greater than a cross-sectional dimension ofthe second portion of the expandable frame.
 20. A replacement mitralvalve configured to be delivered to a native mitral valve and securedrelative to a native mitral valve annulus, the native mitral valvepositioned between a left atrium and a left ventricle, the replacementmitral valve comprising: an expandable frame comprising a proximal endand a distal end and having a longitudinal axis extending between theproximal end and the distal end, the expandable frame configured toradially expand and contract for deployment within the native mitralvalve; a first anchoring portion sized to at least partially engage anatrial side of the native mitral valve annulus, wherein when theexpandable frame is in an expanded configuration: a first section of thefirst anchoring portion extends radially outwardly of the longitudinalaxis and at least partially proximally; and a second section of thefirst anchoring portion proximal to the first section extends radiallyinwardly from the first section towards the longitudinal axis and atleast partially proximally; a second anchoring portion distal to thefirst anchoring portion and comprising a plurality of anchors extendingfrom the expandable frame sized for placement on a ventricular side ofthe native mitral valve annulus, wherein when the expandable frame is inan expanded configuration, the plurality of anchors extend at leastpartially proximally toward the first anchoring portion; and a valvebody connected to the expandable frame.
 21. The replacement mitral valveof claim 20, wherein the replacement mitral valve is shaped such that,after the replacement mitral valve has been delivered to the nativemitral valve and expanded, at least a portion of the first anchoringportion contacts tissue on the atrial side of the native mitral valveannulus and at least a portion of the second anchoring portion contactstissue on the ventricular side of the native mitral valve annulus. 22.The replacement mitral valve of claim 21, wherein the replacement mitralvalve is shaped such that, after the replacement mitral valve has beendelivered to the native mitral valve and expanded, at least a portion ofthe second anchoring portion contacts at least one of the native mitralvalve annulus and leaflets of the native mitral valve.
 23. Thereplacement mitral valve of claim 21, wherein the replacement mitralvalve is shaped such that, after the replacement mitral valve has beendelivered to the native mitral valve and expanded, the expandable framecomprises a cylindrical portion extending within a chamber of the heartwith at least a portion of the valve body positioned within thecylindrical portion such that the valve body is located substantiallyoutside of the native valve annulus.
 24. The replacement mitral valve ofclaim 20, wherein the first section of the first anchoring portionextends radially outwardly to define a shoulder.
 25. The replacementmitral valve of claim 20, wherein when the expandable frame is in anexpanded configuration, the expandable frame has a substantiallyconstant outer diameter from where the plurality of anchors of thesecond anchoring portion connect to the expandable frame to where thefirst section of the first anchoring portion extends radially outwardlyof the longitudinal axis.
 26. The replacement mitral valve of claim 20,wherein when the expandable frame is in an expanded configuration, thesecond section of the first anchoring portion, after extending radiallyinwardly from the first section towards the longitudinal axis and atleast partially proximally, extends in a direction generally parallel tothe longitudinal axis.
 27. The replacement mitral valve of claim 20,wherein when the expandable frame is in an expanded configuration, across-sectional dimension of the proximal end of the expandable frame isless than a cross-sectional dimension of the second anchoring portion.28. The replacement mitral valve of claim 20, wherein when theexpandable frame is in an expanded configuration, a cross-sectionaldimension of the proximal end of the expandable frame is about the sameas a cross-sectional dimension of the distal end of the expandableframe.
 29. The replacement mitral valve of claim 20, wherein when theframe is in an expanded configuration, the expandable frame comprises acylindrical portion which extends away from both the first and secondanchoring portions towards one of the ends of the frame, wherein atleast a portion of the valve body is positioned within the cylindricalportion when the expandable frame is in an expanded configuration.